CAMSAP3 Suppresses Breast Cancer Metastasis and Serves as an Independent Prognostic Marker.

IntroductionBreast cancer metastasis remains the leading cause of disease-related mortality. While calmodulin-regulated spectrin-associated protein 3 (CAMSAP3) has been implicated as a metastasis suppressor in other cancers, its role in breast cancer remains poorly defined. This study aimed to investigate the prognostic significance and functional impact of CAMSAP3 in breast cancer.MethodsCAMSAP3 protein expression was evaluated by immunohistochemistry in 137 primary breast cancer specimens and correlated with clinicopathological features and survival outcomes. Kaplan-Meier and Cox regression analyses were performed to assess distant relapse-free survival (DRFS). Functional assays, including wound healing and Transwell invasion assays, were conducted in MDA-MB-231 and HCC1937 cells following CAMSAP3 overexpression or knockdown. External mRNA-level validation was performed using the Kaplan-Meier Plotter database.ResultsHigh CAMSAP3 expression was significantly associated with favorable features, including lower histological grade, hormone receptor positivity, reduced proliferation index, and fewer triple-negative phenotypes. Patients with high CAMSAP3 expression exhibited significantly improved DRFS, which was independently validated using a public mRNA dataset showing improved distant metastasis-free survival (DMFS). In vitro, CAMSAP3 overexpression inhibited migration and invasion of MDA-MB-231 cells, while CAMSAP3 knockdown enhanced these phenotypes in HCC1937 cells.ConclusionCAMSAP3 is a potential metastasis suppressor and independent prognostic marker in breast cancer. Its high expression is associated with less aggressive tumor characteristics and improved survival, possibly through inhibition of cancer cell migration and invasion.